1. Field of the Invention
The present invention relates to an image processing result display apparatus, and an image processing result display method, that display results of image processing executed according to instructions from an operator on a display, and a program for implementing the method.
2. Description of the Related Art
Conventionally, in an image processing result display apparatus that displays image processing results, such as a copying machine, image data for display is generally compressed and stored in an internal memory or an external storage device connected to a PCI (Peripheral Component Interconnect) bus (for example, refer to Japanese Laid-Open Patent Publication (Kokai) No. 2003-202855).
FIG. 10 is a block diagram schematically showing the construction of a conventional image processing result display apparatus.
As shown in FIG. 10, the conventional image processing result display apparatus is comprised of a CPU 101 that controls the entire apparatus, a main memory 102 that temporarily stores various input information and arithmetic results, an LCD (Liquid Crystal Display) controller 103 that controls an LCD 107 to display image processing results on the LCD 107, a color reducing unit 106 that carries out color reduction, a zooming/scrolling unit 105, a JPEG (Joint Photographic Expert Group) decoder 104, a PCI bus controller 108, and an external storage device 110.
The CPU 101, the main memory 102, the LCD controller 103, the JPEG decoder 104, the zooming/scrolling unit 105, the color reducing unit 106, and the PCI bus controller 108 are connected together via a local bus 100. The PCI bus controller 108 and the external storage device 110 are connected together via a PCI bus 109.
The LCD 107 displays image data having a resolution that is designated by the operator. The image data is generated from JPEG-compressed image data of, for example, four types of resolutions of 25 dpi (Dot per Inch), 50 dpi, 100 dpi, and 200 dpi, that are stored in the external storage device 110. Image data of each resolution are each divided into tiles of 32 pixels×32 pixels, and each tile is JPEG-compressed.
If the resolution of a display image is designated to be, for example, 150 dpi, the JPEG decoder 104 reads JPEG-compressed image data of tiles of an image data portion required for display from 100 dpi and 200 dpi JPEG-compressed image data that are stored in the external storage device 110. The JPEG decoder 104 then expands the read compressed image data and writes the expanded image data onto the main memory 102.
The zooming/scrolling unit 105 generates image data of 150 dpi from the expanded 100 dpi and 200 dpi image data and writes the generated 150 dpi image data onto the main memory 102. The image data generated and written to the main memory 102 in this manner is displayed on the LCD 107.
FIG. 11 a flowchart showing a zooming/scrolling process carried out by the above conventional image processing result display apparatus.
When a scroll operation is instructed while a 150 dpi zoom image is being displayed, the JPEG decoder 104 reads JPEG-compressed image data that should be added in the direction of scrolling, from the external storage device 110 (step S101), expands the read image data, and writes the expanded image data onto the main memory 102 (step S102). Next, the zooming/scrolling unit 105 generates zoom image data from the expanded image data and writes the generated zoom image data onto the main memory 102. The CPU 101 adds the generated image data to a portion of image data that is to be displayed even after scrolling, out of the image data currently being displayed, and writes the resulting image data as new image data onto the main memory 102 (step S103). The CPU 101 then gives an instruction to the color reducing unit 106 to carry out color reduction (step S104), and replaces the image data displayed on the LCD 107 by the newly generated image data (step S105). By this procedure, the display image appears to have been scrolled.
However, with the above conventional image processing result display apparatus, whenever scrolling is carried out, image data to be added is read from the storage device and then subjected to JPEG expansion/zooming. Due to this, processing takes a long time, and further, if the storage device is connected via a PCI bus or the like, it takes even a longer time to read data. Therefore, the scroll operation cannot follow instructions from the operator and thus it is not possible to carry out smooth scrolling.